The great Apostle John wrote today’s Epistle to defend Christianity against the confusion and error that was being taught by the false teachers of his day. He wrote this Epistle to re-emphasize to his readers, both then and now, that we either exhibit the sound doctrine, obedience, and love that characterize all Christians, or else we are not true Christians at all. And he explained to us how we can be sure that we know and understand the true teachings of God!